I chose one that looked somewhat cleaner than the rest, picked it open, cleaned and lubed it up, then started impressioning. After about 30 minutes I had a working key. The blank I used was an Ilco W1. Once I was done I tried the key on the rest of the locks and found that they are keyed alike. The one I impressioned got a polish treatment (pictured) with some Brass-O and now it shines like new. As I get time I plan to polish all the others as well.
first make sure that you are not, in fact, simply surrounded by assholes." William Gibson